# import sys
# sys.setrecursionlimit(1<<31-1)
# matrix = '''110010000011111110101001001001101010111011011011101001111110
# 010000000001010001101100000010010110001111100010101100011110
# 001011101000100011111111111010000010010101010111001000010100
# 101100001101011101101011011001000110111111010000000110110000
# 010101100100010000111000100111100110001110111101010011001011
# 010011011010011110111101111001001001010111110001101000100011
# 101001011000110100001101011000000110110110100100110111101011
# 101111000000101000111001100010110000100110001001000101011001
# 001110111010001011110000001111100001010101001110011010101110
# 001010101000110001011111001010111111100110000011011111101010
# 011111100011001110100101001011110011000101011000100111001011
# 011010001101011110011011111010111110010100101000110111010110
# 001110000111100100101110001011101010001100010111110111011011
# 111100001000001100010110101100111001001111100100110000001101
# 001110010000000111011110000011000010101000111000000110101101
# 100100011101011111001101001010011111110010111101000010000111
# 110010100110101100001101111101010011000110101100000110001010
# 110101101100001110000100010001001010100010110100100001000011
# 100100000100001101010101001101000101101000000101111110001010
# 101101011010101000111110110000110100000010011111111100110010
# 101111000100000100011000010001011111001010010001010110001010
# 001010001110101010000100010011101001010101101101010111100101
# 001111110000101100010111111100000100101010000001011101100001
# 101011110010000010010110000100001010011111100011011000110010
# 011110010100011101100101111101000001011100001011010001110011
# 000101000101000010010010110111000010101111001101100110011100
# 100011100110011111000110011001111100001110110111001001000111
# 111011000110001000110111011001011110010010010110101000011111
# 011110011110110110011011001011010000100100101010110000010011
# 010011110011100101010101111010001001001111101111101110011101'''
#
# matrix = matrix.split('\n')
# matrix = list(map(list,matrix))
# n,m = len(matrix), len(matrix[0])
# f = [(-1,0),(1,0),(0,-1),(0,1)]
# def dfs(x,y):
#     global cnt,matrix[x][y] = '0'
#     cnt += 1
# for fx,fy in f:
#     nx,ny = x + fx, y + fy
#     if 0<=nx<n and 0<=ny<m and matrix[nx][ny] == '1':
#         dfs(nx,ny) # 进行深搜ans = 0
# for i in range(n):
#     for j in range(m):
#         if matrix[i][j] == '1':cnt = 0 # 求取连通分量
#         dfs(i,j)
#         ans = max(ans,cnt) # 取最大连通分量
# print(ans)
